When 2 moles of C2H6(g) react with O2(g) to form CO2(g) and H2O(g) according to the following equation, 2.86×103 kJ of energy are evolved. 2C2H6(g)+ 7O2(g)----->4CO2(g) + 6H2O(g) Is this reaction endothermic or exothermic? _________(endothermic or exothermic) What is the value of q? _______ kJ

When one mol of KOH is neutralized by sulfuric acid, q=56 kJ. (This is called the heat of neutralization.) At 23.7C, 25.0 mL of 0.475 M H2SO4 is neutralized by 0.613 M KOH in a coffee-cup calorimeter. Assume that the specific heat of all solutions is 4.18J/gC, that the density of all solutions is 1.00 g/mL, and that volumes are additive. (a) How many mL of KOH is required to neutralize H2SO4? (b) What is the final temperature of the solution?

Consider the following reaction in a vessel with a movable piston. R(g)+T(g)X(g)As the reaction takes place, the piston loses 1072 J of heat. The piston moves down and the surroundings do 549 J of work on the system. What is E?

How much heat is absorbed by a 44.7-g piece of leadwhen its temperature increases by 65.4°C?

Hypothetical elements A2 and B2 react according to the following equation, forming the compound AB. A2(aq)+B2(aq)2AB(aq);H=+271kJ/mol If solutions A2(aq) and B2(aq), starting at the same temperature, are mixed in a coffee-cup calorimeter, the reaction that occurs is a exothermic, and the temperature of the resulting solution rises. b endothermic, and the temperature of the resulting solution rises. c endothermic, and the temperature of the resulting solution falls. d exothermic, and the temperature of the resulting solution falls. e exothermic or endothermic, depending on the original and final temperatures.

Chlorine dioxide, ClO2, is a reddish yellow gas used in bleaching paper pulp. The average speed of a ClO2 molecule at 25C is 306 m/s. What is the kinetic energy (in joules) of a ClO2 molecule moving at this speed?

Graphite is burned in oxygen to give carbon monoxide and carbon dioxide. If the product mixture is 33% CO and 67% CO2 by mass, what is the heat from the combustion of 1.00 g of graphite?

A 21.3-mL sample of 0.977 M NaOH is mixed with 29.5 mL of 0.918 M HCl in a coffee-cup calorimeter (see Section 6.6 of your text for a description of a coffee-cup calorimeter). The enthalpy of the reaction, written with the lowest whole-number coefficients, is 55.8 kJ. Both solutions are at 19.6C prior to mixing and reacting. What is the final temperature of the reaction mixture? When solving this problem, assume that no heat is lost from the calorimeter to the surroundings, the density of all solutions is 1.00 g/mL, the specific heat of all solutions is the same as that of water, and volumes are additive.

Sulfur dioxide gas reacts with oxygen, O2(g), to produce SO3(g). This reaction releases 99.0 kJ of heat (at constant pressure) for each mole of sulfur dioxide that reacts. Write the thermochemical equation for the reaction of 2 mol of sulfur dioxide, and then also for the decomposition of 3 mol of sulfur trioxide gas into oxygen gas and sulfur dioxide gas. Do you need any other information to answer either question?

What mass of acetylene, C2H2(g), must be burned to produce 3420 kJ of heat, given that its enthalpy of combustion is 1301 kJ/mol? Compare this with the answer to Exercise 5.91 and determine which substance produces more heat per gram.